This application is not referenced in any microfiche appendix.
This disclosure is to a system and a method for separating components from a mixed phase inlet stream.
The invention generally relates to a type of gas/oil/water separator. Separators of this type are typically process vessels that may operate at atmospheric or above atmospheric pressure. The main function of the separator system is to segregate immiscible phases of an inlet stream. The inlet stream may be in the form of gas that carries with it immiscible liquid components, frequently referred to as a xe2x80x9cwet gasxe2x80x9d stream or may more likely be a mixed phase stream of oil, water and gas. The function of the separator of this invention is to separate out the gas and separate liquid components from a mixed phase inlet stream.
The systems and method of this disclosure are basically applicable to: (1) removing liquid dispersed in a gas stream, such as in which the liquid is of relatively little volume compared to the gas; and (2) removing gas from a liquid stream in which the gas is of a relatively small proportion (by volume) of the stream. In the first instance, the separation process is generally referred to as xe2x80x9cgas demistingxe2x80x9d and in the second instance, the separation process is generally referred to as xe2x80x9cliquid degassingxe2x80x9d. The liquid component of a mixed phase inlet usually is made up of immiscibly mixed oil and water that are separated and separately withdrawn.
Separators for separating components from a mixed phase inlet stream are commonly utilized in the oil and gas industry, specifically in oil and gas production, oil refining and gas processing, and are also used in the mining industry, chemical plants, water treatment facilities, pulp and paper plants and pharmaceutical manufacturing facilities.
Separation of immiscible components of a mixed phase inlet stream usually depends on the force of gravity. Gravity can be either natural gravityxe2x80x94that is, the pull of mass towards the center of the earth or created (artificial) gravitational forces such as are generated by centrifugal separators. Natural gravity is usually used by flowing a stream having immiscible components into a vessel which provides a quiescent zone -that is, a relatively undisturbed environment that allows gravity to act on heavier components of the stream and move them into a downward part of the vessel. This movement has the counteraction of the lighter components of the stream migrating to an upward part of the vessel. In this way, the heavier componentsxe2x80x94that is, liquids, can be withdrawn from the lower part of the vessel and the lighter componentsxe2x80x94that is, gases, withdrawn from an upper part of the vessel. In the petroleum industry, the liquid component in a mixed phase stream is typically oil and water that are separately withdrawn.
Separators commonly have an inlet momentum absorber or deflector to reduce the momentum of the incoming stream and to distribute liquid and gas within the separator vessel. This kinetic energy reduction initiates phase separation inside a separator vessel.
Artificial gravity can be generated by the use of a vortex tube or tubes. A vortex tube is typically an elongated tube having a cylindrical interior wall that is preferably vertically mounted or at least mounted with a vertically downward tangent. The vortex tube (or each vortex tube if more than one is employed) has an inlet arranged so that mixed phase inlet stream flowing therein tangentially intersects the interior wall of the vortex tube and flows around the interior wall to thereby create centrifugal force serving to move the heavier componentxe2x80x94that is, liquid components, towards the wall of the vortex tube while the lighter component (gas) is forced towards the interior of the tube. In a typical vortex tube, the gas is withdrawn from an upper central vortex opening while the liquid components are withdrawn from a liquid outlet in the bottom portion of the tube.
This invention herein is a system and method employing a separator apparatus in combination with a vortex tube or a vortex tube cluster. In a vortex tube cluster, each tube receives a portion of the incoming flow stream, which enters tangentially, creating rotational flow. More particularly, this application is a system for separating oil, water and gas from an inlet stream using a sloped vessel of the type that takes full advantage of a vortex tube inlet system to more effectively and efficiently remove the liquid component from an inlet stream and for separating the liquid component into heavier and lighter portions such as to separate oil and water from a crude oil emulsion inlet and for separately discharging the gas and separate liquid components.
For additional background information relating to the general subject matter of this disclosure reference may be had to the following previously issued United States patents:
A better understanding of the invention will be obtained from the following description and claims, taken in conjunction with the attached drawings.
The invention herein relates to a method, and a system for practicing the method, of separating gas and entrained immiscible liquid components from a mixed-phase inlet stream. The method includes the steps of introducing a mixed-phase stream (that may hereinafter be referred to as an xe2x80x9cinlet streamxe2x80x9d) into the inlet of a treatment vessel, the vessel having a dry gas outlet, an oil outlet and a water outlet. The inlet stream is passed into at least one vortex tube but in the preferred practice of the invention, into a cluster of vortex tubes. Whether one or a plurality of vortex tubes, the inlet stream passes into one or more vortex inlets wherein the stream is caused to circumferentially swirl within cylindrical walls of the vortex tubesxe2x80x94that is, the inlet stream rapidly rotates. This rapid rotation causes the liquid components and any entrained solids, to be moved to the circumference of the rotating stream. A gas opening is provided centrally within an upper portion of each vortex tube and a liquids/solids outlet in a lower end of each vortex tube.
Particularly, the invention herein provides a system for separating gas, oil and water from an inlet stream including an elongated sloped vessel having a vortex tube cluster therein through which the inlet stream is introduced and by which gas is extracted. The vessel includes a gas outlet adjacent an upper end of the sloped vessel with oil and water outlets adjacent the lower end.
A weir within the vessel establishes a liquid level above which gas accumulates. The volumetric area within the sloped vessel above the liquid level increases in the direction towards the gas outlet. This increased volumetric area reduces the velocity of gas flow towards the exit and provides a quiescent gas zone in which any remaining entrained liquid droplets can effectively settle out. In like manner, the volumetric area below the liquid level increases in the direction towards the lower end of the vessel providing a low turbulence zone for oil/water separation. The sloped vessel is uniquely adapted for use of a vortex tube cluster.